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  <section id="configure-file">
<span id="command:configure_file"></span><h1><a class="toc-backref" href="#id1" role="doc-backlink">configure_file</a><a class="headerlink" href="#configure-file" title="Link to this heading">¶</a></h1>
<nav class="contents" id="contents">
<p class="topic-title">Contents</p>
<ul class="simple">
<li><p><a class="reference internal" href="#configure-file" id="id1">configure_file</a></p>
<ul>
<li><p><a class="reference internal" href="#options" id="id2">Options</a></p></li>
<li><p><a class="reference internal" href="#transformations" id="id3">Transformations</a></p></li>
<li><p><a class="reference internal" href="#example" id="id4">Example</a></p></li>
<li><p><a class="reference internal" href="#see-also" id="id5">See Also</a></p></li>
</ul>
</li>
</ul>
</nav>
<p>Copy a file to another location and modify its contents.</p>
<div class="highlight-cmake notranslate"><div class="highlight"><pre><span></span><span class="nf">configure_file(</span><span class="nv">&lt;input&gt;</span><span class="w"> </span><span class="nv">&lt;output&gt;</span>
<span class="w">               </span><span class="p">[</span><span class="no">NO_SOURCE_PERMISSIONS</span><span class="w"> </span><span class="p">|</span><span class="w"> </span><span class="no">USE_SOURCE_PERMISSIONS</span><span class="w"> </span><span class="p">|</span>
<span class="w">                </span><span class="no">FILE_PERMISSIONS</span><span class="w"> </span><span class="nv">&lt;permissions&gt;...</span><span class="p">]</span>
<span class="w">               </span><span class="p">[</span><span class="no">COPYONLY</span><span class="p">]</span><span class="w"> </span><span class="p">[</span><span class="no">ESCAPE_QUOTES</span><span class="p">]</span><span class="w"> </span><span class="p">[</span><span class="no">@ONLY</span><span class="p">]</span>
<span class="w">               </span><span class="p">[</span><span class="no">NEWLINE_STYLE</span><span class="w"> </span><span class="p">[</span><span class="no">UNIX</span><span class="p">|</span><span class="no">DOS</span><span class="p">|</span><span class="no">WIN32</span><span class="p">|</span><span class="no">LF</span><span class="p">|</span><span class="no">CRLF</span><span class="p">]]</span><span class="nf">)</span>
</pre></div>
</div>
<p>Copies an <code class="docutils literal notranslate"><span class="pre">&lt;input&gt;</span></code> file to an <code class="docutils literal notranslate"><span class="pre">&lt;output&gt;</span></code> file while performing
<a class="reference internal" href="#transformations">transformations</a> of the input file content.</p>
<p>If the input file is modified the build system will re-run CMake to
re-configure the file and generate the build system again.
The generated file is modified and its timestamp updated on subsequent
cmake runs only if its content is changed.</p>
<section id="options">
<h2><a class="toc-backref" href="#id2" role="doc-backlink">Options</a><a class="headerlink" href="#options" title="Link to this heading">¶</a></h2>
<p>The options are:</p>
<dl>
<dt><code class="docutils literal notranslate"><span class="pre">&lt;input&gt;</span></code></dt><dd><p>Path to the input file.  A relative path is treated with respect to
the value of <span class="target" id="index-0-variable:CMAKE_CURRENT_SOURCE_DIR"></span><a class="reference internal" href="../variable/CMAKE_CURRENT_SOURCE_DIR.html#variable:CMAKE_CURRENT_SOURCE_DIR" title="CMAKE_CURRENT_SOURCE_DIR"><code class="xref cmake cmake-variable docutils literal notranslate"><span class="pre">CMAKE_CURRENT_SOURCE_DIR</span></code></a>.  The input path
must be a file, not a directory.</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">&lt;output&gt;</span></code></dt><dd><p>Path to the output file or directory.  A relative path is treated
with respect to the value of <span class="target" id="index-0-variable:CMAKE_CURRENT_BINARY_DIR"></span><a class="reference internal" href="../variable/CMAKE_CURRENT_BINARY_DIR.html#variable:CMAKE_CURRENT_BINARY_DIR" title="CMAKE_CURRENT_BINARY_DIR"><code class="xref cmake cmake-variable docutils literal notranslate"><span class="pre">CMAKE_CURRENT_BINARY_DIR</span></code></a>.
If the path names an existing directory the output file is placed
in that directory with the same file name as the input file.
If the path contains non-existent directories, they are created.</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">NO_SOURCE_PERMISSIONS</span></code></dt><dd><div class="versionadded">
<p><span class="versionmodified added">Added in version 3.19.</span></p>
</div>
<p>Do not transfer the permissions of the input file to the output file.
The copied file permissions default to the standard 644 value
(-rw-r--r--).</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">USE_SOURCE_PERMISSIONS</span></code></dt><dd><div class="versionadded">
<p><span class="versionmodified added">Added in version 3.20.</span></p>
</div>
<p>Transfer the permissions of the input file to the output file.
This is already the default behavior if none of the three permissions-related
keywords are given (<code class="docutils literal notranslate"><span class="pre">NO_SOURCE_PERMISSIONS</span></code>, <code class="docutils literal notranslate"><span class="pre">USE_SOURCE_PERMISSIONS</span></code>
or <code class="docutils literal notranslate"><span class="pre">FILE_PERMISSIONS</span></code>).  The <code class="docutils literal notranslate"><span class="pre">USE_SOURCE_PERMISSIONS</span></code> keyword mostly
serves as a way of making the intended behavior clearer at the call site.</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">FILE_PERMISSIONS</span> <span class="pre">&lt;permissions&gt;...</span></code></dt><dd><div class="versionadded">
<p><span class="versionmodified added">Added in version 3.20.</span></p>
</div>
<p>Ignore the input file's permissions and use the specified <code class="docutils literal notranslate"><span class="pre">&lt;permissions&gt;</span></code>
for the output file instead.</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">COPYONLY</span></code></dt><dd><p>Copy the file without replacing any variable references or other
content.  This option may not be used with <code class="docutils literal notranslate"><span class="pre">NEWLINE_STYLE</span></code>.</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">ESCAPE_QUOTES</span></code></dt><dd><p>Escape any substituted quotes with backslashes (C-style).</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">&#64;ONLY</span></code></dt><dd><p>Restrict variable replacement to references of the form <code class="docutils literal notranslate"><span class="pre">&#64;VAR&#64;</span></code>.
This is useful for configuring scripts that use <code class="docutils literal notranslate"><span class="pre">${VAR}</span></code> syntax.</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">NEWLINE_STYLE</span> <span class="pre">&lt;style&gt;</span></code></dt><dd><p>Specify the newline style for the output file.  Specify
<code class="docutils literal notranslate"><span class="pre">UNIX</span></code> or <code class="docutils literal notranslate"><span class="pre">LF</span></code> for <code class="docutils literal notranslate"><span class="pre">\n</span></code> newlines, or specify
<code class="docutils literal notranslate"><span class="pre">DOS</span></code>, <code class="docutils literal notranslate"><span class="pre">WIN32</span></code>, or <code class="docutils literal notranslate"><span class="pre">CRLF</span></code> for <code class="docutils literal notranslate"><span class="pre">\r\n</span></code> newlines.
This option may not be used with <code class="docutils literal notranslate"><span class="pre">COPYONLY</span></code>.</p>
</dd>
</dl>
</section>
<section id="transformations">
<h2><a class="toc-backref" href="#id3" role="doc-backlink">Transformations</a><a class="headerlink" href="#transformations" title="Link to this heading">¶</a></h2>
<p><a class="reference internal" href="../manual/cmake-language.7.html#cmake-language-variables"><span class="std std-ref">Variables</span></a> referenced in the input
file content as <code class="docutils literal notranslate"><span class="pre">&#64;VAR&#64;</span></code>, <code class="docutils literal notranslate"><span class="pre">${VAR}</span></code>, <code class="docutils literal notranslate"><span class="pre">$CACHE{VAR}</span></code>, and
<a class="reference internal" href="../manual/cmake-language.7.html#cmake-language-environment-variables"><span class="std std-ref">environment variables</span></a>
referenced as <code class="docutils literal notranslate"><span class="pre">$ENV{VAR}</span></code>, will each be replaced with the current value
of the variable, or the empty string if the variable is not defined.
Furthermore, input lines of the form</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="cp">#cmakedefine VAR ...</span>
</pre></div>
</div>
<p>will be replaced with either</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="cp">#define VAR ...</span>
</pre></div>
</div>
<p>or</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="cm">/* #undef VAR */</span>
</pre></div>
</div>
<p>depending on whether <code class="docutils literal notranslate"><span class="pre">VAR</span></code> is set in CMake to any value not considered
a false constant by the <span class="target" id="index-0-command:if"></span><a class="reference internal" href="if.html#command:if" title="if"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">if()</span></code></a> command.  The &quot;...&quot; content on the
line after the variable name, if any, is processed as above.</p>
<p>Unlike lines of the form <code class="docutils literal notranslate"><span class="pre">#cmakedefine</span> <span class="pre">VAR</span> <span class="pre">...</span></code>, in lines of the form
<code class="docutils literal notranslate"><span class="pre">#cmakedefine01</span> <span class="pre">VAR</span></code>, <code class="docutils literal notranslate"><span class="pre">VAR</span></code> itself will expand to <code class="docutils literal notranslate"><span class="pre">VAR</span> <span class="pre">0</span></code> or <code class="docutils literal notranslate"><span class="pre">VAR</span> <span class="pre">1</span></code>
rather than being assigned the value <code class="docutils literal notranslate"><span class="pre">...</span></code>. Therefore, input lines of the form</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="cp">#cmakedefine01 VAR</span>
</pre></div>
</div>
<p>will be replaced with either</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="cp">#define VAR 0</span>
</pre></div>
</div>
<p>or</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="cp">#define VAR 1</span>
</pre></div>
</div>
<p>Input lines of the form <code class="docutils literal notranslate"><span class="pre">#cmakedefine01</span> <span class="pre">VAR</span> <span class="pre">...</span></code> will expand
as <code class="docutils literal notranslate"><span class="pre">#cmakedefine01</span> <span class="pre">VAR</span> <span class="pre">...</span> <span class="pre">0</span></code> or <code class="docutils literal notranslate"><span class="pre">#cmakedefine01</span> <span class="pre">VAR</span> <span class="pre">...</span> <span class="pre">1</span></code>,
which may lead to undefined behavior.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.10: </span>The result lines (with the exception of the <code class="docutils literal notranslate"><span class="pre">#undef</span></code> comments) can be
indented using spaces and/or tabs between the <code class="docutils literal notranslate"><span class="pre">#</span></code> character
and the <code class="docutils literal notranslate"><span class="pre">cmakedefine</span></code> or <code class="docutils literal notranslate"><span class="pre">cmakedefine01</span></code> words. This whitespace
indentation will be preserved in the output lines:</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="cp">#  cmakedefine VAR</span>
<span class="cp">#  cmakedefine01 VAR</span>
</pre></div>
</div>
<p>will be replaced, if <code class="docutils literal notranslate"><span class="pre">VAR</span></code> is defined, with</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="cp">#  define VAR</span>
<span class="cp">#  define VAR 1</span>
</pre></div>
</div>
</div>
</section>
<section id="example">
<h2><a class="toc-backref" href="#id4" role="doc-backlink">Example</a><a class="headerlink" href="#example" title="Link to this heading">¶</a></h2>
<p>Consider a source tree containing a <code class="docutils literal notranslate"><span class="pre">foo.h.in</span></code> file:</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="cp">#cmakedefine FOO_ENABLE</span>
<span class="cp">#cmakedefine FOO_STRING &quot;@FOO_STRING@&quot;</span>
</pre></div>
</div>
<p>An adjacent <code class="docutils literal notranslate"><span class="pre">CMakeLists.txt</span></code> may use <code class="docutils literal notranslate"><span class="pre">configure_file</span></code> to
configure the header:</p>
<div class="highlight-cmake notranslate"><div class="highlight"><pre><span></span><span class="nf">option(</span><span class="no">FOO_ENABLE</span><span class="w"> </span><span class="s">&quot;Enable Foo&quot;</span><span class="w"> </span><span class="no">ON</span><span class="nf">)</span>
<span class="nf">if(</span><span class="no">FOO_ENABLE</span><span class="nf">)</span>
<span class="w">  </span><span class="nf">set(</span><span class="no">FOO_STRING</span><span class="w"> </span><span class="s">&quot;foo&quot;</span><span class="nf">)</span>
<span class="nf">endif()</span>
<span class="nf">configure_file(</span><span class="nb">foo.h.in</span><span class="w"> </span><span class="nb">foo.h</span><span class="w"> </span><span class="no">@ONLY</span><span class="nf">)</span>
</pre></div>
</div>
<p>This creates a <code class="docutils literal notranslate"><span class="pre">foo.h</span></code> in the build directory corresponding to
this source directory.  If the <code class="docutils literal notranslate"><span class="pre">FOO_ENABLE</span></code> option is on, the
configured file will contain:</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="cp">#define FOO_ENABLE</span>
<span class="cp">#define FOO_STRING &quot;foo&quot;</span>
</pre></div>
</div>
<p>Otherwise it will contain:</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="cm">/* #undef FOO_ENABLE */</span>
<span class="cm">/* #undef FOO_STRING */</span>
</pre></div>
</div>
<p>One may then use the <span class="target" id="index-0-command:target_include_directories"></span><a class="reference internal" href="target_include_directories.html#command:target_include_directories" title="target_include_directories"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">target_include_directories()</span></code></a> command to
specify the output directory as an include directory:</p>
<div class="highlight-cmake notranslate"><div class="highlight"><pre><span></span><span class="nf">target_include_directories(</span><span class="nv">&lt;target&gt;</span><span class="w"> </span><span class="p">[</span><span class="no">SYSTEM</span><span class="p">]</span><span class="w"> </span><span class="o">&lt;</span><span class="no">INTERFACE</span><span class="p">|</span><span class="no">PUBLIC</span><span class="p">|</span><span class="no">PRIVATE</span><span class="o">&gt;</span><span class="w"> </span><span class="s">&quot;${CMAKE_CURRENT_BINARY_DIR}&quot;</span><span class="nf">)</span>
</pre></div>
</div>
<p>so that sources may include the header as <code class="docutils literal notranslate"><span class="pre">#include</span> <span class="pre">&lt;foo.h&gt;</span></code>.</p>
</section>
<section id="see-also">
<h2><a class="toc-backref" href="#id5" role="doc-backlink">See Also</a><a class="headerlink" href="#see-also" title="Link to this heading">¶</a></h2>
<ul class="simple">
<li><p><span class="target" id="index-0-command:file"></span><a class="reference internal" href="file.html#generate" title="file(generate)"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">file(GENERATE)</span></code></a></p></li>
</ul>
</section>
</section>


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    <h3>Table of Contents</h3>
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<li><a class="reference internal" href="#">configure_file</a><ul>
<li><a class="reference internal" href="#options">Options</a></li>
<li><a class="reference internal" href="#transformations">Transformations</a></li>
<li><a class="reference internal" href="#example">Example</a></li>
<li><a class="reference internal" href="#see-also">See Also</a></li>
</ul>
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</ul>

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